This invention relates to improved powdered or pulverent polymer materials to be transformed into functional parts, prototypes, models or tools (referred to as parts herein) by a SLS machine such as those developed at The University of Texas at Austin and currently sold by 3D Systems of Valencia Calif. and EOS GmbH Electro Optical Systems of Munich Germany.
SLS was invented by this inventor in the mid 1980s at The University of Texas at Austin. A methods and apparatus for sintering a powder into a shaped article in an SLS machine are disclosed in U.S. Pat. Nos. 4,247,508 to Housholder; 4,863,538; 5,017,753; 5,132,143; 5,316,580; 5,597,589; 5,616,294 and 5,639,070 to Deckard; 5,155,324 to Deckard et al; 4,938,816 and 5,053,090 to Beaman et al. Multiple material systems for SLS are disclosed in U.S. Pat. Nos. 4,944,817; 5,076,869: 5,296,062 and 5,382,308 to Bourell et al. Semi-crystalline organic polymers for SLS are disclosed in U.S. Pat. Nos. 5,342,919; 5,527,877; 5,648,450; 5,990,268 and 6,136,948 to Dickens et. al. The significance of the SLS processing temperature window is also discussed. Use of a Nylon 12 powder precipitated from solution in SLS is disclosed in U.S. Pat. No. 6,245,281 B1 to Scholten et. al.